In the previous post, I talked about the Tan Kah Kee Young Inventor’s Award (TKKYIA). In this post, I will be talking about what are my detailed plans for the personal transporter.
The motors are from a car windshield wiper which was also used previously on another personal transporter. It has a gearbox to give it some torque while sacrificing speed, which is not really what is needed. Its fairly heavy, so this will ensure stability.
Testing the motor
A motor driver will be used to drive those motors using PWM. The PWM speed is regulated by the motor shield which receives serial commands via a Rx line from the arduino. This particular model is the Sabertooth 2X25. It can drive up to 25A per channel, but we only need about 800mA – 1.5A, so at normal operation, the currents are way lower than its limit.
Testing the HC-06 Bluetooth Module
Right now I’m just testing different android apps that send char characters to the bluetooth module and using the serial monitor to see the output. Originally I wanted it to be accelerometer controlled, but the app I found doesn’t really work on newer versions of android. There was another app of which I can customise every slider and button on the phone side. However, it is a paid app so in free mode I could only use it for 10 secs. The link to app can be accessed here.
The other apps only send a ‘f’ for forward, ‘b’ for backward and so on. There are predefined in the app so in the arduino sketch I have to match those commands. They also support moving forward while turning slightly. (8 directions of movement). Most likely I will use this method.
The wood panel used is plywood and I had it cut to 40cm X 45cm. I gave some extra tolerance so that I don’t have to recut in case everything doesn’t fit. I can cut the wood to the smallest possible size later on.
The battery is rather large, so I have to see how it fits into the transporter. I have not gotten it yet, so I did not drill holes for the motor mounts. Currently I have 2 possible layouts as shown below, if the battery is really large, I would have to place it in between the motors.
Mounting the Motors
The motors have a M8 standard holes, so what I’ll do is screw them in from the top of the wood panel.